Almost a century ago, neurosurgeons performed the first surgical disconnections of the frontal lobe (leucotomies) in psychiatric diseases, and then frontal lobectomies (FL), mainly in epilepsy. Since these initial resections, which induced a high rate of neurologic consequences, FL were conceptually associated to a combination of cognitive, emotional and behavioral symptoms known under the term of “frontal syndrome”. However, because of a recent paradigmatic shift from a localizationist to a connectomal theory of neural processing, and thanks to advances in brain mapping techniques, the traditional concept of irrevocable frontal syndrome generated by FL has been called into question [1Duffau H. The huge plastic potential of adult brain and the role of connectomics: new insights provided by serial mappings in glioma surgery Cortex 2014 ;  58 : 325-337 [cross-ref]

Cliquez ici pour aller à la section Références]. Indeed, in the more recent field of neurooncological surgery, massive FL have been achieved up to individual eloquent networks identified by intraoperative direct electrical stimulation both at cortical and subcortical levels [2Duffau H. The “frontal syndrome” revisited: lessons from electrostimulation mapping studies Cortex 2012 ;  48 : 120-131 [cross-ref]

Cliquez ici pour aller à la section Références]. Using this philosophy of functional mapping-based resection, the existence of a huge potential of cortical plasticity has been evidenced, allowing a preservation of neurologic and neurocognitive status, including executive functions, mentalizing and metacognition, following unilateral or even bilateral FL [3Lemaitre A.L., Herbet G., Duffau H., Lafargue G. Preserved metacognitive ability despite unilateral or bilateral anterior prefrontal resection Brain Cogn 2018 ;  120 : 48-57 [cross-ref]

Cliquez ici pour aller à la section Références]. Such a functional compensation is possible owing to the preservation of the white matter tracts that represent the limitation of neuroplasticity [4Herbet G., Maheu M., Costi E., Lafargue G., Duffau H. Mapping neuroplastic potential in brain-damaged patients Brain 2016 ;  139 : 829-844 [cross-ref]

Cliquez ici pour aller à la section Références]. In fact, to prevent the occurrence of a “frontal syndrome”, which is most of the time the consequence of a dysconnectionism syndrome, the goal of FL is to surgically spare the intra-lobar connectivity (e.g. the frontal aslant tract), the inter-lobar long-range association fibers (e.g. the superior longitudinal fasciculus, arcuate fasciculus and inferior fronto-occipital fasciculus) as well as the projection fibers (e.g. the fronto-striatal tract) [5Duffau H. Stimulation mapping of white matter tracts to study brain functional connectivity Nat Rev Neurol 2015 ;  11 : 255-265 [cross-ref]

Cliquez ici pour aller à la section Références]. This improved knowledge of the functional connectome enables to significantly increase the overall survival while preserving the quality of life of brain tumor patients [6Duffau H. Diffuse low-grade glioma, oncological outcome and quality of life: a surgical perspective Curr Opin Oncol 2018 ; [in press].

Cliquez ici pour aller à la section Références]. In addition, these new insights into cerebral processing can be applied to other fields of neurosurgery, such as brain-computer interface, to neurology and neurorehabilitation, by elaborating specific programs of cognitive remediation, and to basic neurosciences by proposing new behavioral models challenging the classical localist dogma.